Answer: A
In the first step, this question tests literary knowledge.
The second step, "There is less frost at the end of the year, and the grass and trees on the earth know when spring comes" comes from Zhang Shi's "The Beginning of Spring Occasionally" in the Song Dynasty, which means that the frost gradually decreases at the end of the year, and the grass and trees on the earth are the first to know about the return of spring. . All I could see before my eyes was a scene of vitality, with green waves on the water swaying in the east wind. According to the Song of the Twenty-Four Solar Terms: The spring rain shocks the spring and clears the valley, and the summer is full of awns and the summer heat is connected. There is dew in autumn, cold frost in autumn, and snow in winter and slight severe cold in winter. It can be seen that the twenty-four solar terms described belong to the beginning of spring. The earliest solar term of the year is the beginning of spring, so choose option A.